Potentially Deadly Error Triggers Worldwide Investigation

The incident occurred at Melbourne Airport, reports The Sydney
Morning Herald, and triggered an immediate check of over 50 planes
serviced by the apparently mis-labelled nitrogen gas cart.

An aircraft engineer noticed the error and tipped off the Civil
Aviation Safety Authority, which ruled it was an isolated incident.
However, an unnamed aviation source told the Herald the mistake may
have affected "hundreds of planes worldwide.

"Any international jet that passed through Melbourne and was
serviced by Qantas could have had nitrogen pumped into its oxygen
tanks," said the source.

Qantas reportedly took delivery of the nitrogen cart 10 months
ago, and "it looked exactly like the old oxygen cart. When the
attachments did not fit they went and took them off the old oxygen
cart and started using it.

"This could have affected at least
175 planes."

Nitrogen is commonly used on commercial airliners to fill
landing gear tires. The gas is lighter than regular air, and is
resistant to moisture which can degrade rubber.

Though nitrogen makes up the bulk of breathable air, pure
nitrogen can be deadly to humans as it causes asphyxiation,
starving the body of oxygen.

"If there was an emergency and the pilot took nitrogen instead
of oxygen, instead of gaining control of the aircraft he would
black out and it would be all over. It's a pretty serious mistake,"
Dr. Ian Millar, director of the hyperbaric medicine unit at
Melbourne's Alfred Hospital, told the Herald.

A spokeswoman with the ATSB said Qantas identified 21 aircraft
at risk due to the error, and another 30 that may have received low
amounts of nitrogen in their oxygen supplies during top-off
operations. No actual incidents of damage or safety issues have
been reported.